scholarly journals Uplift Resistance Capacity of Anchor Piles used in Marine Aquaculture

2021 ◽  
Author(s):  
Fukun Gui ◽  
Jianqiao Kong ◽  
Dejun Feng ◽  
Xiaoyu Qu ◽  
Fang Zhu ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Failure Load ◽  
Lateral Displacement ◽  
Single Pile ◽  
Initial Tension ◽  
Marine Aquaculture ◽  
Pile Diameter ◽  
Single Piles ◽  
Uplift Resistance ◽  
Better Than

Abstract Anchor piles are widely used in marine aquaculture, and their uplift resistance capacity largely determines their safety, especially in harsh ocean environments. However, a practical guide on its design and installation is wanting. Laboratory experiments were conducted to investigate the effect of the initial tension angle, pile diameter, embedded depth, and pile configuration on the uplift resistance capacity of anchor piles for marine aquaculture under oblique loads. The results show that increasing the initial tension angle of circular and square single piles can significantly improve the uplift resistance capacity. The failure load of the square single pile was slightly higher than that of the circular single pile. Increasing the pile diameter can effectively improve the failure load and delay the development speed of the pile top displacement. Increasing the embedded depth can effectively improve the failure load and increase the lateral displacement of the pile top. The uplift resistance capacity of the dual anchor piles was better than that of the single anchor piles. The layout configuration has little effect on the failure load, but has a large effect on the displacement development.

scholarly journals Uplift resistance capacity of anchor piles used in marine aquaculture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fukun Gui ◽  
Jianqiao Kong ◽  
Dejun Feng ◽  
Xiaoyu Qu ◽  
Fang Zhu ◽  
...  
Keyword(s):  
Failure Load ◽  
Lateral Displacement ◽  
Ccd Camera ◽  
The Body ◽  
Single Pile ◽  
Initial Tension ◽  
Marine Aquaculture ◽  
Pile Diameter ◽  
Single Piles ◽  
Uplift Resistance

AbstractAnchor piles are widely used in marine aquaculture, and the safety is largely determined by the uplift resistance capacity,especially in harsh ocean environments. However, there are few practical guides to the design and installation of the anchor piles for mooring the body of marine aquaculture equipment. Laboratory experiments were conducted to investigate the effect of the initial tension angle, pile diameter, embedded depth, and pile configuration on the uplift resistance capacity of anchor piles under oblique loads. CCD camera and load cell were utilized to measure the corresponding displacement and load, respectively. The results show that increasing the initial tension angle of circular and square single piles can significantly improve the uplift resistance capacity. The failure load of the square single pile was slightly higher than that of the circular single pile. Increasing the pile diameter can effectively improve the failure load and delay the development speed of the pile top displacement. Increasing the embedded depth can effectively improve the failure load and increase the lateral displacement of the pile top. The uplift resistance capacity of the dual anchor piles was better than that of the single anchor piles. The layout configuration has little effect on the failure load, but has a large effect on the displacement development.

The Review on the Modified Exponential Model in the Fitting of Loading-Settlement Curves of Single Pile

2014 ◽  
Vol 501-504 ◽  
pp. 892-904
Author(s):  
Yu Chuan Shuan ◽  
Bo Yang Ding ◽  
Ming Ouyang
Keyword(s):  
Static Load ◽  
Exponential Model ◽  
Measured Data ◽  
Load Test ◽  
Hyperbolic Model ◽  
Single Pile ◽  
Static Load Test ◽  
Single Piles ◽  
Test Pile ◽  
Better Than

According to optimized fitting analysis for measured data in static load test of 22 different types of single piles, a new modified exponential model was proposed by authors in this paper. In comparison between the hyperbolic model and the integrated exponential curve model, the correlativity coefficients R of the modified exponential model were over 0.996. The fitting effect of the model of proposed in this paper is better than that of other models above-mentioned. The deviations between fitting and measured data in static load test for single pile was small, especially, in the tail pasts of fitting curves, the mean deviations of 2 test pile given in the paper are 1.61% and 1.99% respectively. The modified exponential model can be better described Q-S curves of single piles. It can be used to better evaluate the ultimate bearing capacity of single piles.

scholarly journals Modeling Laterally Loaded Single Piles Accounting for Nonlinear Soil-Pile Interactions

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Maryam Mardfekri ◽  
Paolo Gardoni ◽  
Jose M. Roesset
Keyword(s):  
Finite Element ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Soil Mass ◽  
Fe Model ◽  
The Finite Element Method ◽  
Pile Diameter ◽  
Single Piles ◽  
Laterally Loaded

The nonlinear behavior of a laterally loaded monopile foundation is studied using the finite element method (FEM) to account for soil-pile interactions. Three-dimensional (3D) finite element modeling is a convenient and reliable approach to account for the continuity of the soil mass and the nonlinearity of the soil-pile interactions. Existing simple methods for predicting the deflection of laterally loaded single piles in sand and clay (e.g., beam on elastic foundation,p-ymethod, and SALLOP) are assessed using linear and nonlinear finite element analyses. The results indicate that for the specific case considered here thep-ymethod provides a reasonable accuracy, in spite of its simplicity, in predicting the lateral deflection of single piles. A simplified linear finite element (FE) analysis of piles, often used in the literature, is also investigated and the influence of accounting for the pile diameter in the simplified linear FE model is evaluated. It is shown that modeling the pile as a line with beam-column elements results in a reduced contribution of the surrounding soil to the lateral stiffness of the pile and an increase of up to 200% in the predicted maximum lateral displacement of the pile head.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

scholarly journals Large-Scale Laboratory Experiments on Mussel Dropper Lines in Ocean Surface Waves

2020 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
Rebekka Gieschen ◽  
Christian Schwartpaul ◽  
Jannis Landmann ◽  
Lukas Fröhling ◽  
Arndt Hildebrandt ◽  
...  
Keyword(s):  
Large Scale ◽  
Laboratory Experiments ◽  
Blue Mussel ◽  
Farming Systems ◽  
Quality Parameter ◽  
Large Wave ◽  
Marine Aquaculture ◽  
Ocean Surface Waves ◽  
Wave Flume ◽  
Waves And Currents

The rapid growth of marine aquaculture around the world accentuates issues of sustainability and environmental impacts of large-scale farming systems. One potential mitigation strategy is to relocate to more energetic offshore locations. However, research regarding the forces which waves and currents impose on aquaculture structures in such conditions is still scarce. The present study aimed at extending the knowledge related to live blue mussels (Mytilus edulis), cultivated on dropper lines, by unique, large-scale laboratory experiments in the Large Wave Flume of the Coastal Research Center in Hannover, Germany. Nine-months-old live dropper lines and a surrogate of 2.0 m length each are exposed to regular waves with wave heights between 0.2 and 1.0 m and periods between 1.5 and 8.0 s. Force time histories are recorded to investigate the inertia and drag characteristics of live mussel and surrogate dropper lines. The surrogate dropper line was developed from 3D scans of blue mussel dropper lines, using the surface descriptor Abbott–Firestone Curve as quality parameter. Pull-off tests of individual mussels are conducted that reveal maximum attachment strength ranges of 0.48 to 10.55 N for mussels that had medium 3.04 cm length, 1.60 cm height and 1.25 cm width. Mean drag coefficients of CD = 3.9 were found for live blue mussel lines and CD = 3.4 for the surrogate model, for conditions of Keulegan–Carpenter number (KC) 10 to 380, using regular wave tests.

scholarly journals Study on the horizontal bearing characteristics of pile foundation in coral sand

2021 ◽  
Author(s):  
Chunyan Wang ◽  
Hanlong Liu ◽  
Xuanming Ding ◽  
Chenglong Wang ◽  
Qiang Ou
Keyword(s):  
Lateral Displacement ◽  
Experimental Studies ◽  
Deformation Characteristic ◽  
Bending Moment ◽  
Silica Sand ◽  
Pile Head ◽  
Pile Diameter ◽  
Coral Sand ◽  
Horizontal Pressure ◽  
Different Diameters

This paper presents the horizontal bearing characteristics of piles in coral sand and silica sand from comparative experimental studies. A total of 6 model piles with different diameters are tested. The horizontal bearing capacity, deformation characteristic, bending moment, p-y curve, the change in soil horizontal pressure, as well as the particle breakage behaviour of coral sand are investigated. The results show that, in coral sand foundation, the horizontal bearing capacities of piles and the increments of soil horizontal pressures are obviously greater than those in silica sand. Accordingly, the lateral displacement, the rotation of pile head, the bending moment and the corresponding distribution depth in coral sand are significantly smaller than that in silica sand. The p-y curves indicate that the horizontal stiffness of coral sand is greater than that of silica sand. Remarkably, the breakage behaviour of coral sand is mainly distributed in the range of 10 times pile diameter depth and 5 times pile diameter width on the side where the sand is squeezed by pile. Furthermore, in coral sand, the influence of pile size is more pronounced, the squeezing force generated by pile spread farther and its influence range is larger compared to those in silica sand.

The effects of hatchery and wild ancestry and experience on the relative ability of steelhead trout fry (Oncorhynchus mykiss) to avoid a benthic predator

1995 ◽  
Vol 52 (11) ◽  
pp. 2476-2482 ◽  
Author(s):  
Barry A. Berejikian
Keyword(s):  
Oncorhynchus Mykiss ◽  
Predator Avoidance ◽  
Laboratory Experiments ◽  
Test Period ◽  
Natural Environments ◽  
Steelhead Trout ◽  
Visual Exposure ◽  
Natural Stream ◽  
Relative Ability ◽  
Better Than

Differences in selection regimes between hatchery and natural environments and environmental stimuli, among other factors, have the potential to cause differences in predator avoidance ability between hatchery and wild steelhead trout fry (Oncorhynchus mykiss). In two separate laboratory experiments, fry raised from eggs of wild Quinault River steelhead trout survived predation by prickly sculpin (Cottus asper) significantly better than size-matched offspring of a locally derived hatchery population, which were reared under similar conditions. Wild fry also survived predation better than hatchery fry in natural stream enclosures over a 3-day test period. Experience, in the form of 50-min visual exposure to sculpin predation on "sacrificial" steelhead trout, improved the ability of fry from both populations to avoid predation by sculpin. Wild-experienced fry were eaten in the fewest number of trials followed by wild-naive, hatchery-experienced, and hatchery-naive fry. The results of this study are consistent with the hypothesis that innate predator avoidance ability has been negatively altered through domestication and that attempts to condition hatchery-reared steelhead to avoid predators may be limited for domesticated populations.

scholarly journals Postharvest Drying of Leyland Cypress, Eastern Red Cedar, and Fraser Fir Christmas Trees

HortScience ◽  
1995 ◽  
Vol 30 (7) ◽  
pp. 1427-1428 ◽  
Author(s):  
L. Eric Hinesley ◽  
Layne K. Snelling
Keyword(s):  
Laboratory Experiments ◽  
Juniperus Virginiana ◽  
Pressure Potential ◽  
Fraser Fir ◽  
Eastern Red Cedar ◽  
Red Cedar ◽  
Christmas Trees ◽  
Xylem Pressure Potential ◽  
Better Than

Postharvest drying of Leyland cypress [× Cupressocyparis leylandii (A.B. Jacks. & Dallim.)] branches was intermediate between eastern red cedar (Juniperus virginiana L.) and Fraser fir [Abies fraseri (Pursh) Poir.] in two laboratory experiments. Leyland cypress rehydrated without adverse effect until xylem pressure potential reached –4.0 to –5.0 MPa (shoot moisture content = 60% to 65%). For branches continuously maintained in water, Fraser fir and Leyland cypress kept equally well over 4 weeks of display, but Leyland cypress lasted longer than Fraser fir over 8 weeks. Postharvest keeping quality of Leyland cypress and Fraser fir was better than that of eastern red cedar.

scholarly journals ANALISIS DISPLACEMENT PADA TIANG TUNGGAL DENGAN MENGGUNAKAN METODE PUSHOVER ANALYSIS

2020 ◽  
Vol 3 (2) ◽  
pp. 349
Author(s):  
Pieter Kristianto Syafrin ◽  
Chaidir Anwar Makarim ◽  
Amelia Yuwono
Keyword(s):  
Soft Soil ◽  
Pushover Analysis ◽  
Lateral Force ◽  
Pile Foundations ◽  
Engineering System ◽  
Single Pile ◽  
Drift Ratio ◽  
Single Piles ◽  
Definition Of ◽  
Capacity Method

All construction that is engineered and built rests on the ground must be supported by foundation. Foundation is the lowest part of structure that is done first and has important function in the construction of a building to continue the burden on the structure which will then be forwarded to the soil below. The term upper structure is generally used to describe part of an engineering system that carries a burden on the foundation or bottom structure. On the basis of the definition of this foundation, it can be explained that foundation is the most important part of the engineering system. (Bowles, 1991). Single pile foundations can be used on various types of soil and one of them is soft soil. To analyze elastic and non-elastic single piles in the condition of free heads and fixed heads in various dimensions, they were designed according to SNI 1726: 2012 and evaluated using the spectrum capacity method regulated in ATC-40. Based on the results of the study, a pile drift ratio and performace point values will be obtained which describe the behavior of the pile due to gradual lateral force. Results obtained describe the behavior of all the single pile models analyzed. AbstrakSemua konstruksi yang direkayasa dan dibangun bertumpu di tanah harus ditopang oleh fondasi. Fondasi adalah bagian terendah dari struktur yang dikerjakan terlebih dahulu dan memiliki fungsi penting dalam pembangunan sebuah bangunan untuk meneruskan beban struktur di atasnya yang kemudian akan diteruskan ke tanah dan bebatuan yang berada di bawah. Istilah struktur atas umumnya digunakan untuk menggambarkan bagian dari sistem rekayasa yang membawa beban pada pondasi atau struktur bawah. Atas dasar definisi yayasan ini, dapat dijelaskan bahwa yayasan adalah bagian terpenting dari sistem teknik. (Bowles, 1991). Fondasi tiang tunggal dapat digunakan pada berbagai jenis tanah dan salah satunya adalah tanah lunak. Untuk dapat menganalisis tiang tunggal elastis dan tidak elastis dalam kondisi kepala bebas dan kepala tetap dalam berbagai dimensi, mereka dirancang berdasarkan SNI 1726: 2012 dan dievaluasi menggunakan metode kapasitas spektrum yang diatur dalam ATC-40. Berdasarkan hasil penelitian, akan diperoleh suatu nilai pile drift ratio dan performace point yang menggambarkan perilaku tiang akibat diberikan gaya lateral secara bertahap.. Hasil yang diperoleh menggambarkan perilaku semua pemodelan tiang tunggal yang dianalisis.

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